4f4x
From Proteopedia
Y-family DNA polymerase chimera Dbh-Dpo4-Dpo4 #2
Structural highlights
FunctionDPO4_SACS2 Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. It is involved in translesional synthesis.DPO4_SULAC Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. May be involved in translesional synthesis (By similarity). Publication Abstract from PubMedY-family polymerases help cells tolerate DNA damage by performing translesion synthesis opposite damaged DNA bases, yet they also have a high intrinsic error rate. We constructed chimeras of two closely related Y-family polymerases that display distinctly different activity profiles and found that the polypeptide linker that tethers the catalytic polymerase domain to the C-terminal DNA-binding domain is a major determinant of overall polymerase activity, nucleotide incorporation fidelity, and abasic site-bypass ability. Exchanging just 3 out of the 15 linker residues is sufficient to interconvert the polymerase activities tested. Crystal structures of four chimeras show that the conformation of the protein correlates with the identity of the interdomain linker sequence. Thus, residues that are more than 15 A away from the active site are able to influence many aspects of polymerase activity by altering the relative orientations of the catalytic and DNA-binding domains. Y-Family Polymerase Conformation Is a Major Determinant of Fidelity and Translesion Specificity.,Wilson RC, Jackson MA, Pata JD Structure. 2012 Dec 11. pii: S0969-2126(12)00420-0. doi:, 10.1016/j.str.2012.11.005. PMID:23245850[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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